#!/pro/bin/perl
# This is the recursive version of sccs2git
# Combining all SCCS repos to one single git repo
use strict;
use warnings;
use VCS::SCCS;
use File::Find;
my %sccs_ext;
my @sccs;
find (sub { $File::Find::dir =~ m{(?:^|/)SCCS$} and m/^s\./ or return;
            push @sccs, $File::Find::name;
            m/\.(\w+)$/ and $sccs_ext{$1}++;
          }, glob "*");
@sccs or die "No SCCS source files to convert\n";
-d ".git" and die ".git already exists\n";
system "git init";
# http://www.kernel.org/pub/software/scm/git/docs/gitattributes.html
# could be explored to write checkout hooks that translate SCCS
# keywords to actual content. Would be hard to translate back
sub pr_date
{
    my @dt = localtime shift;
    sprintf "%s %02d-%02d-%4d %02d:%02d:%02d",
        (qw( Sun Mon Tue Wed Thu Fri Sat ))[$dt[6]],
        $dt[3], $dt[4] + 1, $dt[5] + 1900,
        $dt[2], $dt[1], $dt[0];
    } # pr_date
# fire up GFI
chomp (my $branchname = qx(git symbolic-ref HEAD));
open my $gfi, "|-", qw(git fast-import --quiet);
my $mark;
# use a best guess at user, hostname, etc.  FIXME: add authors map :)
use Time::Local;
use Net::Domain;
my $domain = Net::Domain::hostdomain () || "procura.nl";
my %tzoffset;
my $tzoffset = sub {
    use integer;
    my $offset_s = timegm (localtime ($_[0])) - $_[0];
    my $off = abs $offset_s / 60;
    my ($off_h, $off_m) = ($off / 60, $off % 60);
    $tzoffset{$offset_s} ||= ( $offset_s >= 0 ? "+" : "-" )
        . sprintf "%02d%02d", $off_h, $off_m;
    };
# Submit in the same sequence as the original
my %sccs;
my %file;
my @fail;
foreach my $f (sort @sccs) {
    my $sccs;
    eval { $sccs = VCS::SCCS->new ($f) };
    unless ($sccs) {
        warn "Cannot convert $f\n";
        push @fail, $f;
        next;
        }
    # GIT supports get-hooks, to translate on retrieval
    # But it will be useless as you cannot translate back
    $sccs->set_translate ("SCCS");
    my $fn = $sccs->file ();
    $file{$fn}++;
    foreach my $rm (@{$sccs->revision_map ()}) {
        my ($rev, $vsn) = @{$rm};
        my $delta = $sccs->delta ($rev);
        $sccs{pack "NA*", $delta->{stamp}, $fn} = [ $sccs, $rev, ++$mark ];
        my $data = scalar $sccs->body ($rev);
        print { $gfi } "blob\nmark :", $mark,
                           "\ndata ", length ($data),
                           "\n", $data, "\n";
        printf STDERR "%-20s %3d %8s  %s\r", $fn, $rev, $vsn,
            pr_date ($delta->{stamp});
        }
    print STDERR "\n";
    }
foreach my $c (sort keys %sccs) {
    my ($sccs, $rev, $mark) = @{$sccs{$c}};
    my $fn    = $sccs->file ();
    my %delta = %{$sccs->delta ($rev)};
    my $stamp = pr_date ($delta{stamp});
    my $vsn   = $delta{version};
    printf STDERR "%-20s %3d %6s  %s %s %s\n", $fn, $rev, $vsn,
        $stamp, $delta{date}, $delta{"time"};
    print { $gfi } "commit ", $branchname, "\n";
    print { $gfi } "committer ", $delta{committer},
        " <", $delta{committer}, "@", $domain, "> ",
        $delta{stamp}, " ", $tzoffset->($delta{stamp}), "\n";
    # tradition is to save all potentially useful but
    # uncategorized metadata as RFC822-style headers in the commit
    # message
    my $mr  = $delta{mr} || ""; $mr =~ s/^-$//;
    $mr  and $mr  = "SCCS-mr: $mr";
    $vsn and $vsn = "SCCS-vsn: $vsn";
    my $cmnt = $delta{comment} || "";
    $cmnt ||= "(no message)";
    $cmnt  .= "\n";
    my $msg  = join "\n", $cmnt, grep m/\S/, $mr, $vsn;
    print { $gfi } "data ", length ($msg), "\n$msg\n";
    my $mode = $delta{flags}{x} ? "755" : "644";
    print { $gfi } "M $mode :$mark $fn\n";
    print { $gfi } "\n";
    }
print { $gfi } "checkpoint\n";
close $gfi;
system "git", "checkout";
system "git", "reset", "--hard";
open my $gi, ">", ".gitignore";
print $gi <<EOG;
SCCS
core
old
save
*.log
*.out
*.sv
*.t[gb]z
*.zip
EOG
exists $sccs_ext{as} and print $gi <<EOG;
*.[af]o
*.[af]q
*.al
*.bk
*.fa
*.hz
EOG
exists $sccs_ext{c}  and print $gi <<EOG;
*.[oa]
a.out
EOG
exists $sccs_ext{ic} and print $gi <<EOG;
*.ec
*.u
udir
EOG
close $gi;
system "git", "add", ".gitignore";
system "git", "commit", "-m", "Add default ignore list";
@fail and print STDERR join "\n    ",
    "The following files could not be converted and were skipped:", @fail, "\r";